Flexible are commonly produced in a variety of forms, ranging from laminar-type relatively flexible membrane valves to silicon-based flexible valves which are generally non-laminar in shape. The construction of non-laminar, self-closing flexible-like valves for instance, generally comprises a concave or convex shaped head portion, with at least one slit, a side wall portion, and a flange.
Generally speaking, the term “laminar”, as set forth this application, relates to forms which have a substantially uniform thickness with major surfaces being parallel to one another. The term “non-laminar” concerns forms which have a thickness that varies and in which the shape does not have major surfaces that are parallel to one-another.
Non-laminar valves are often used in association with closures which are themselves used in association with containers holding such consumable products as liquid soap and ketchup. They have the quality that when a user applies pressure to the container walls (for example by squeezing) the head portion of the valve responds to this increased pressure within the container by opening outwardly in the form of “petals”. The fluid contained within the container then passes through the slit of the head portion of the valve. Further, the container walls are typically resilient such that when the user stops squeezing them, they move back to their original shape, thus increasing the volume within the container and, accordingly, reducing the pressure within the container. This reduced pressure sucks the open “petals” of the valve back to their original closed position. Such self-closing property is aided by the concave shape of the valve head.
According to one known method, to retain these valves within closures by means of retaining pieces, for example, the valve is first positioned within the closure at the relevant place and then a retaining piece is pushed over the valve until it snaps over a retaining bead within the closure. In this manner, the valve is held captive between the closure and the retaining piece.
Another conventional method of retaining such valves within closures involves positioning the valve within the closure and then bending a deformable ring, which forms part of the closure itself, over so that it crimps the valve in place. The valve is thus held captive against the closure by the crimped ring.
Containers that are used for holding and dispensing food products, such as ketchup, often have peelable foil membranes affixed over the mouth of the container that have to be removed prior to the first dispensing. To remove this foil, the user must first unscrew the closure from the container, then peel off the membrane, and finally re-screw the closure back onto the container. Once this has been carried out, the user may then squeeze the container and force the product through the valve and the associated spout or orifice situated in the closure, as discussed above.
It has been known, however, for some users to merely push a pen or other such object through the orifice of the closure, which then passes through the valve and, in turn, through the foil membrane underneath to pierce this foil without the need to remove the closure from the container. Although this may appear to save time, not only is hygiene a possible cause for concern, but more importantly it has been known for the pen or other such object to push the valve out from its crimped position, possibly by dislodging the retaining piece from the closure. The loose valve may then be dispensed along with product when the container is squeezed, since it is flexible enough to pass through the orifice. Furthermore, because the valve may be covered in product, it may be disguised and accordingly ingested by someone who was not aware it was there. Choking could result. The retaining piece, however, would not pass through the orifice since it is typically manufactured from harder material of a size that is greater than the size of the orifice.
Another common problem with these types of flexible valves is that because they are so supple, they are accordingly quite difficult to handle and position within the closure during assembly. This slows down assembly of the closures. Additionally, the valves have a tendency to stick to one another and, although talcum powder is used to reduce this problem, it can also slow closure assembly.
A device is, therefore, desired that overcomes problems associated with valve suppleness and flexibility so that it is not only impossible for valves, which become loose within containers, to pass through closure orifices, but also handleability may be improved to increase efficiency of the manufacture of closures.